The proposed research has two objectives. The first is aimed at understanding the normal postnatal development of the dorsal lateral geniculate nucleus in the cat. Light and electron microscopic methods will be used to investigate the maturation of geniculate cells and the synaptic relations which they form. The second objective is to assess the influence of both partial and complete visual deprivation on the normal sequence of lateral geniculate development; and, in particular, to determine if there exists a specific developmental period during which the lateral geniculate is especially sensitive to the effects of deprivation.